[IA64] fixes configs and add default config for ia64 xen domU

This patch fixes xen related Kconfigs and add default config
file for ia64 xen domU.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NTony Luck <aegl@agluck-desktop.(none)>

arch/ia64/Kconfig

@@ -221,7 +221,11 @@ config IA64_HP_SIM
 
 config IA64_XEN_GUEST
 	bool "Xen guest"
+	select SWIOTLB
 	depends on XEN
+	help
+	  Build a kernel that runs on Xen guest domain. At this moment only
+	  16KB page size in supported.
 
 endchoice
 

arch/ia64/xen/Kconfig

@@ -8,8 +8,7 @@ config XEN
 	depends on PARAVIRT && MCKINLEY && IA64_PAGE_SIZE_16KB && EXPERIMENTAL
 	select XEN_XENCOMM
 	select NO_IDLE_HZ
-
-	# those are required to save/restore.
+	# followings are required to save/restore.
 	select ARCH_SUSPEND_POSSIBLE
 	select SUSPEND
 	select PM_SLEEP